The CloudPage snippet is what turns Nimbus from "an automation finished" into "step 3 of 7 — the SQL query — timed out after 41 minutes." It also makes reruns possible. Setting it up is a one-time task per Business Unit.
SFMC's Event Notification Service tells Nimbus *that* an automation ran, but not the internals of the run. To read per-step timing, activity status, query targets, and import results, code has to execute inside your SFMC account.
The REST and SOAP APIs are not enough on their own. They report a summary of what happened, but they do not expose everything Nimbus needs to rebuild and rerun a failed automation — the full activity configuration, step ordering, and run-time detail required to construct an accurate, trimmed copy of the automation and fire it. A CloudPage is the supported place to host code that *can* reach that detail.
Nimbus generates a small AMPScript snippet for you to publish on a CloudPage. When an automation finishes, Nimbus calls that CloudPage; the snippet uses SFMC's internal APIs to gather the enriched detail — along with the configuration needed to rebuild and rerun the automation — and posts it back to Nimbus.
After credentials are verified, Nimbus shows the snippet on the setup screen. You can also reach it later from Settings → Connection → Deploy snippet. Copy the whole block — it is unique to this Business Unit. The block itself contains no secret; the generated secret it relies on lives in a separate code snippet that Nimbus deploys automatically into Content Builder.
Nimbus Enrichment Endpoint.Paste the published URL into the CloudPage URL field in Nimbus and click Verify. Nimbus calls the page, confirms the snippet responds and reports its version, and saves the endpoint.
Nimbus also seeds a few small data extensions in your account — supporting tables the snippet uses. This runs automatically, and you can re-run it from Settings → Connection with Initialize.
The snippet evolves. Nimbus records the deployed snippet version and compares it to the current version on every enrichment call. When your CloudPage is behind, Nimbus redeploys the snippet automatically — you do not need to copy and paste it again. You can always check the deployed-vs-current version under Settings → Connection.
The snippet authenticates its callbacks with a generated secret, and you do not have to manage it. Nimbus rotates the secret automatically every 24 hours, updating the Content Builder code snippet each time. Each callback is also protected by a single-use nonce, so replayed requests are rejected.
More fixes are in Troubleshooting.